Week 6 Random Flashcards
Which embyonic layer gives rise to the epihelium? connective tissue?
E: Ectoderm, Mesoderm, Endoderm
C: Mesoderm, Ectoderm (head)
Where is epithelium found?
It lines all cavities and outside surfaces.
What are the functions of epithelia?
Protection
Transcellular Transport (e.g. vessicles for IgA, carrier protein aa & glucose, and diffusion of oxygen in alveoli)
Secretion (exocytosis e.g. hormones)
Absorption (endocytosis e.g. PCT in kidney)
Selective Permeability
Sensory Organ (e.g. taste buds, retina, hair cells)
What is another name for intermediate filaments?
Cytokeratin / Tonofilaments
Characteristic of epithelium
Polarized
Intermediate Filaments
Connected by junctions that form sheets
Separated by basement membrane
Avascular
Rapid regeneration
Simple Squamous Epithelium
Location and Function
Pulmonary aveoli (gaseous exchange)
parietal layer of Bowman’s capsule (fluid exchange)
loop of Henle
inner and middle ear
Endothelium: blood and lympathic vessels (lubrication)
Mesothelium: pleural and peritoneal cavities (reducing friction)

Simple Cuboidal Epithelium
Location and Function
Ducts
Distal tubule in kidney (absorption)
Glands (secretion)
Surface of ovary (protection)

Simple Columnar Epithelium
Location and Example
Oviduct (transport)
Efferentes of testis (transport)
Uterus (secretion)
Small bronchi
Digestive tract (secretion/absorption)
Small gallbladder and excretory ducts in some glands (protection)

Simple Pseudostratified Epithelium
Location and Example
Trachea (secretion/absorption)
Primary bronchi
Epididymis and ductos deferens
Auditory tube (protection)
Tympanic cavity
Lacrimal Sac
Male urethra (transportaion/lubrication)
Large excretory duct

Two types of epithelium
Endothelium: lining of blood vessels and lympathics
Mesothelium: lining of body cavities
Simple vs. Stratified Epithelium
In simple epithelium, all cells lie upon the basement membrane.
Two types of stratified squamous epithelium
nonkeratinized stratified / moist (associated with mucosa) - have alive cells at the surface
keratinized - have denucleated cells at the surface
Stratified Squamous (non-keratinized) Epithelium
Location and Examples
Functions: protection & secretion
Examples: Mouth, Epiglottis, Escophagus, Vocal cords, and Vagina

Stratified Squamous (Keratinized) Epithelium
Location and Function
Epidermis of skin
Protection

Cuboidal Stratified Epithelium
Location and Function
Lining ducts of sweat glands
Absorption and secretion

Stratified Columnar Epithelium
Conjuctiva of eye, some large exretory ducts, portion of male urethra
Secretion, absorption, protection

Transitional Epithelium
Linig of urinary passages from renal calyces to the urethra
Protection and distensible

Functions of basement membrane
Anchoring
Vascular layer
Transcellular transport

What are microenviroments in epithelial cell?
Apical, Laterl, and Basement part.

Surface modifications
Types, Size, Location, and Function
Microvilli (GI tract) “striated border” , 1 um, absoroptin
Microvilli (Kidney) “bursh border”, 1 um, absorption
Stereocilia (Epididymis, DD, innear ear), 2um, absorption
Cilia (Respiratory, Oviduct), 10um, movement of stuff
What supports microvilli?
What is the purpose of microvilli?
Are microvilli pernament?
Actin
Increase surface area
Appear and disapear quickly
Stereocilia vs. Cilia
Cilia are larger and less dense
Stereocilia are smaller and more dense
Celiac sprue
Sensitivity to gluten (component of wheat flour)
Due to loss of microvilli in small intestine
= less absorption and osmotic diarrhea
Kartagener’s Syndrome
Immobile Cilia Syndrome
Dynein arms missing = cilia do not move
Chronic respiratory difficulty including bronchitis and sinusitis



























































